1. Field of the Invention
The present invention generally relates to image processing apparatuses and image processing methods. More particularly, the present invention relates to image data compression/expansion methods.
2. Description of the Related Art
The progress made in computer technology in the recent years has resulted in the development of various hardware resources, such as high-speed processors and large-capacity memories. One particular example is a technology that allows a single processor to logically function as plural processors. Such a processor is capable of executing instructions contained in multiple threads in a parallel manner. The technology is expected to bring about increases in image processing speeds, and several specific image processing methods based on the technology have been proposed.
One example is discussed in Japanese Laid-Open Patent Application No. 2005-259042, which proposes an image processing method and image processing program whereby plural threads for executing image processing are divided into groups according to the processing method used for each of the threads. Another example is discussed in Japanese Patent No. 3,797,013, which proposes an image processing method, a printing device, an image processing system, and a recording medium, whereby the number of processors allocated for halftoning is varied, and the processors allocated are varied depending on resolution.
These image processing methods, however, are not capable of making appropriate divisions to achieve an increase in speed in the case of JPEG 2000, for example, where codes that can be executed in parallel and codes that cannot be executed in parallel coexist, depending on the code that is processed. In other words, it has been difficult to achieve increases in speed in a decoding process for a code according to a JPEG 2000 image processing method, for example, where the code can be decoded independently on an area by area basis, because of the presence of both a portion that allows for parallel processing and another portion that does not allow for parallel processing, thus requiring complicated processing.